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Copyright of Enfermería Neonatal is the property of Fundacion para la Salud Materno Infantil (FUNDASAMIN) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Didasc@lia: Didáctica y Educación is the property of Universitaria de Las Tunas, Centro de Estudios de Didactica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Dilemas Contemporáneos: Educación, Política y Valores is the property of Dilemas Contemporaneos: Educacion, Politica y Valores and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The greatest problems that has been presented in the world, especially in Colombia, is due to an accelerated population growth generated by the overwhelming increase in migrant circulation or mobility of people due to other causes or eventual situations of nature. These social situations have been significantly affecting the urban order of cities, particularly due to the confinement of the population and the increase in environmental pollution that this increase brings, in addition to unhealthiness, poverty, among other factors. To study population growth based on demographic variables and environmental factors, an Artificial Neural Network was built to carry out a data analysis that incorporated related variables such as CO2 and other pollutants. The purpose was to identify the influence of these toxic agents with the growth of a population. Once the dynamic prediction was verified through the neural network, a mathematical model was built to study a specific case of demographic behavior for a certain Colombian region by means of a Forrester Diagram, where the migratory conditions, birth rate, morbidity, mortality, migratory flow (or mobility of people due to other natural events) and pollutants that affect human health mainly in respiratory diseases. The results delivered predictions and the Forrester Diagram confirming the relationship between toxic agents and demographic aspects. [ABSTRACT FROM AUTHOR]

Copyright of Acta Universitaria is the property of Universidad de Guanajuato/Acta Universitaria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Legado de Arquitectura y Diseño is the property of Universidad Autonoma del Estado de Mexico and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

OBJECTIVE: To identify, based on delta CO2 (ΔpCO2), the probability of death within 24 hours of admission to the emergency department in patients with septic shock. MATERIALS AND METHODS: Cases and controls nested in a cohort in patients with septic shock in the emergency department. Cases, patients who died within 24 hours of admission to the emergency department; controls, patients who did not die 24 hours after admission. The veno-arterial difference in carbon dioxide or delta CO2 (ΔpCO2) was calculated on admission to the emergency department with the formula ΔpCO2 = PvCO2-PaCO2, it was measured on a discrete scale and subsequently grouped into two categories (reference point 6). Age was measured in years, stratifying in decades and subsequently in two groups (reference point 60). RESULTS: The sample size was 25 cases and 55 controls. When the discrete scale delta CO2 value and the patient's age in decades were used to estimate the probability of death in patients with septic shock seen in the emergency department, the model was significant (X² = 36.70, p = 0.000). The probability of death was 92.1% when the delta CO2 value was 9 and age 80 or more years. CONCLUSIONS: The model integrated by ΔpCO² and age predicts the probability of dying within 24 hours of admission to the emergency department in patients with septic shock. [ABSTRACT FROM AUTHOR]

Mangrove ecosystems are estimated to have a high impact potential on the global carbon cycle because of their high organic matter content (Dittmar y col., 2006), and consequently a significant importance in CO2 flow as the greenhouse gas with the greatest impact on global warming (Benavides y León, 2007; Caballero, Lozano y Ortega, 2007; CESPA, 2013). In Venezuela, however, studies focusing on this issue are scarce, hence the aim of this research was to specify significant differences in the flow of CO2 in soil colonized by Avicennia germinans, as well as non-rizospheric located in Los Totumos sector. Research developed in three phases was applied: (a) fieldwork, in order to collect 120 surface soil samples (0-20 cm), (b) laboratory, with the purpose of estimating the CO2 flow from the basal breathing method (Anderson, 1982) and (c) statistical analysis, to identify significant differences based on the ANOVA and Tukey test. It is evident that there are significant differences, with flows of 7.51 mg C-CO2 g/24h in the rhyspheric area and 1.49 mg C-CO2 g/24h for non-rizospheric. It is concluded that: (a) microbial activity in the soil, induced by the presence of Avicennia germinans, is possibly contributing to its evolution, and (b) it is reaffirmed that mangrove ecosystems are a source of CO2 and reservoir gas to the impact of climate change. [ABSTRACT FROM AUTHOR]

Copyright of Boletín Económico de ICE is the property of S.G.E.E.I.P.C., Secretaria de Estado de Comercio, Ministerio de Industria, Comercio y Turismo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Stochastic convergence analysis is useful to evaluate the efficiency or inefficiency of economic policies in the medium and long term if the stationarity of the time series studied is known. In this article, we examine the stochastic convergence in primary energy consumption and carbon dioxide (CO2) emissions in Canada, Mexico, and the United States during the period 1965 to 2019. The methodology of this study is based on the application of traditional (Augmented Dickey-Fuller and Phillips-Perron) and last-generation (LM and RALS-LM) unit roots tests to the relative per capita primary energy consumption and per capita CO2 emissions of the three countries. With the econometric analysis carried out, we conclude that both energy consumption and CO2 emissions are divergent in North America. If we solely focus on the period of the North American Free Trade Agreement (NAFTA), we prove the existence of stochastic convergence in primary energy in the United States and emissions of pollutants in Canada. The Mexican economy is divergent in both variables. The governments of the three countries should focus on the introduction of common policies to bolster energy efficiency and reduce pollutants. [ABSTRACT FROM AUTHOR]

Copyright of DYNA - Ingeniería e Industria is the property of Publicaciones Dyna SL and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A statistical correlation study is carried out between numerical data corresponding to the concentration of the suspended particles and the concentration of polluting gases which are obtained from the measurements registered in the Automatic Atmospheric Monitoring Network database (RAMA) for Mexico City and the Metropolitan Area. An important dependency between the gas pairs NO2-NOX, NO-NOX, CO-NO, CO-NOX and the PM2.5-PM10, PMCO-PM10 particle pairs is reported when the study is carried out with reference to a single monitoring station. On the other hand, there is a close relationship between ozone (O3) from one station with ozone to another for different pairs of stations. [ABSTRACT FROM AUTHOR]

Introduction: Burns are part of the management of introduced grasses in Chiapas, Mexico, and this may derive in forest fires. Objectives: To determine fuel load, fire behavior, CO2 emissions, and to get firefighting security issues for jaragua (Hyparrhenia rufa Nees.) grasslands and savannas. Methods: An artificial jaragua grassland and an artificial jaragua savanna were studied at the California and Flores Magón communities, respectively, in La Sepultura Biosphere Reserve. Were measured pre and post-fire fuel loads. Six prescribed burns (three heading and three backing fires) were conducted in each, grassland and savanna, and were measured meteorological as well as fire behavior variables. Emissions were estimated multiplying the consumed fuel load by an emission constant. Results: In the grassland, were obtained the following averages: fuel load, 6.214 t/ ha; residual load, 0.107 t/ha, and CO2 emission, 10.449 t CO2/ha. For the savanna, were recorded 14.119, 2.161 and 20.460 t CO2/ha, respectively, without differences for the pre and post-fire fuel loads between heading and backing fires. For the grassland, the heading fires reached 3.92 m, 1.83 m and 22.3 m/min for flame length, flame depth and fire propagation rate, while for backing fires such values were, respectively: 1.07, 0.23 and 0.67 m/min, with significant differences. For the savanna, heading fires yielded 5.89 m (flame length), 1.53 m (flame depth) and 45.5 m/min (propagation rate), while for backing fires that values were 2.21, 0.76 and 2.8 m/ min, also with significant differences. Conclusions: Under the studied environmental conditions, particularly in the savanna, fire behavior is dangerous so a good prescription and more care must be taken for conducting controlled or prescribed burns. For forest fires, direct firefighting by the head of the fire must be avoided, for is too dangerous; instead it is recommended a firefighting by the back of the fire as well as waiting for a backing fire-advance of it after the fire reaches a ridge. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: Due to the decrease of oil, an alternative energy source such as microalgae biomass is planted to obtain lipids and then biodiesel. Objective: to evaluate the influence of CO2 and the initial concentration of Chlorella vulgaris on lipid production on a laboratory scale. Material and methods: four microalgae growth tests were developed, with CO2 concentrations (0-3%; 3-6%; 6-9%; 9-12%) as a carbon source for biomass production. Start with a cell density of 8.01x106; 1.34x107; 1.74x107 and 1.58x107 cells/mL. The growth parameters were determined in the research group (Ángel, 2012), as a culture medium Foliagro® was used, from the 21 W red light bulbs for cycles of 12/12 hours light/dark, pH 7.5 and a temperature of 24 °C ± 2.5 °C. Results: CO2 concentrations were determined to be between 0-3% and 6-9%, with a cellular production of 3.65x107 cells/mL, satisfactory for the two intervals. The yield of the lipids produced was 61.83%, for a CO2 concentration between 0-3% and 54.49% for a CO2 concentration between 6-9%. Conclusions: for the test 1, the iodine index was 67.91 and the saponification index 107.99; for the test 3 the first was 63.12, and second was 132.63, the parameters that indicate that the lipids produced are useful for the production of biodiesel. [ABSTRACT FROM AUTHOR]

Copyright of Montes is the property of Colegio y Asociación de Ingenieros de Montes and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Author-supplied Abstracts.)

Copyright of Desenvolvimento e Meio Ambiente is the property of Universidade Federal do Parana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ecología Política is the property of Fundacio ENT and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Forest fires and agricultural burns contribute to global climate change, and the latter is a tool that reduces CO2 emissions. The objective of this study was to evaluate the consumption of surface fuels, fire behavior, and emissions in prescribed burns. The hypothesis was that fires affect more fuels and produce more emissions than prescribed burns. Prescribed burns were applied in six randomly-established experimental plots in a tropical oak woodland in Chiapas, Mexico: three heading and three backing fires. Measurements and estimates included: initial and residual fuel loads, consumption factors, and CO2 emissions. Wind speed and direction, temperature and relative humidity, fire spread rate, and flame length were recorded during the burns. In a forest fire, the flame length and the residual fuel load were determined. The t- and the Wilcoxon (under lack of normality) tests were applied. In the heading and backing fires, there were significant differences in the fire spread rate (3.63 and 0.59 m min-1), but there were none in the flame length (0.91 and 0.72 m). The flame length of fires reached 1.94 m, but burns had different results. The total fuel loads in backing and heading fires were 28.393 and 35.512 t ha-1, without differences between them; the consumption factors for backing and headingfires and forest fire reached 92.7, 87.5, and 97.2 %, without showing any difference; however, the forest fire affected aerial fuels. The CO2 emissions reached 44.53, 51.14, and 53.78 t CO2 ha-1. The prescribed burns help to reduce emissions, because their intensity and severity are lower than those of forest fires. Consequently, since burns affect a smaller surface, they help to prevent fires and to reduce emissions. [ABSTRACT FROM AUTHOR]

This article examines the effect of the Kyoto Protocol in Spain, specifically the effectiveness of the objectives of the Kyoto Protocol (KP) on reducing CO2, CH4 and N2O emissions in Spain is studied. For this purpose, it was used two sets of panel data that consist in information at country-level (donor pool made up for country information) and at state-level (donor group made up of information from us states). To obtain a consistent estimate on the effect of the Kyoto Protocol in Spain, the synthetic control method (scm) that allows to perform an adequate contrast hypothesis was used. The findings indicate that there is no reducing effect of emissions for the gases studied; however, the evaluation of the Kyoto Protocol (KP) predicts a serIES of complications that may allude to the findings depending on the econometric approach used. These findings are consistent with the evidence that shows a null effect of the effectiveness of the Kyoto Protocol (KP), and contribute to measure the impact of the Kyoto Protocol (PK) on emissions of CO2, CH4 and N2O in Spain. [ABSTRACT FROM AUTHOR]

Copyright of Agro Productividad is the property of Colegio de Postgraduados and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article has the objective to present the implementation of a transient cycle test for internal combustion engines, particularly the Japanese urban driving cycle 10-Mode on a test bench in a laboratory. This transient cycle was realized in order to compare the mass emissions of CO and CO2 for current E0 fuel and E10 gasohol in similar conditions to the real operation of a vehicle, being used an engine whit carburetor and an engine whit injection fuel. Additionally, fuel consumption of each engine during the driving cycle is reported using gasoline E0 and E10. In this project two different measurement methodologies were used to measure the pollutant emissions, in order to compare and validate the results obtained. The tests were realized in the Engines Laboratory of the Universidad Nacional de Colombia. [ABSTRACT FROM AUTHOR]

The objective of the study was to estimate the carbon footprint (CFP) in the mechanized production of maize, sweet potato and cassava, and to identify and propose mitigation options in the coast of Peru. A survey was conducted in 100 producers from Barranca and Cañete in the Lima region. All production and crop protection practices were registered. The estimation was then conducted with the Excel-based in simulation model; Cool Farm Tool (CFT). Maize in Barranca registered the highest quantity of tillage and applications of pesticides. In both locations, middle to high doses of N were applied to maize whereas sweet potato and cassava received only high doses. When CO2 emissions due to transportation were included in the analyses, farms cultivating cassava in Barranca generated the largest CFP of 267 kg CO2eq·t-1 (adding 132 kg CO2eq·t-1). This addition was similar for all crops. The main sources of greenhouse gases emission (GHE) for all three crops were application (49%), and production (38%) of fertilizers, followed by the use of pesticides (13%). Mitigation options simulated with the CCAFS-MOT included the use of minimum tillage, incorporation of agricultural residues, use of processed organic fertilizers and nitrification inhibitors. By incorporating the four mitigation options GHG reductions in 42%, 22% and 26% were estimated for maize, sweet potato and cassava, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Revista Colombiana de Ciencia Animal - RECIA is the property of Revista Colombiana de Ciencia Animal - RECIA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of the research was to determine the carbon reserve retained under a silvopastoral system with Pinus patula, located in Amazonas, Peru. For the carbon estimation, 06 plants were used by the direct method, the shafts were sectioned every 2 meters and from these were obtained samples of 5 cm of thickness prior to the total weighing. For the branches and leaves the total weight was weighed and samples of 200 g were selected. For the collection of leaf litter and native herbaceous samples, the quadrant method was used and soil samples were collected around each plant. The data were obtained through the formulation of allometric equations and selection of the highest correlation estimated, based on variables such as diameter at chest height (DAP) and height of the stem (AF). As a result, 92.13 t / ha of stored carbon and 337.20 t / ha of carbon equivalent were found. In addition, the research allowed to establish an equation that allows estimating the amount of carbon and CO2 in the pine tree: Dry biomass = 0.6575 * DAP1,1794 (r2 = 0.91). [ABSTRACT FROM AUTHOR]

Copyright of Superficies y Vacío is the property of Sociedad Mexicana de Ciencia y Tecnologia de Superficies y Materiales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista La Tadeo de Arte is the property of La Fundacion Universidad de Bogota Jorge Tadeo Lozano and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista ION is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista ION is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The exploitation of unconventional oil and gas is based on an energy model that is being questioned today and where a reassessment is now proving necessary, based on new geoethic values of environmental sustainability and economic management not based on speculation. The correct management of the environmental risks derived from this use of the subsoil requires a regulating body together with legislation to ensure that no decisions be made with any purpose other than that of protecting the environment together with public participation to ensure transparency throughout the process and the full appraisal of any uncertainties. [ABSTRACT FROM AUTHOR]

With the purpose of estimating carbon sequestration in aboveground biomass of an agroforestry systems consisting of coconut (Cocos nucifera), Leucaena leucocephala Var. Cunningham in high density, and Cuba grass CT-115 (Pennisetum purpureum), a study was carried out on a sandy a soil loam. A randomized block design with split plot arrangement was used with four treatments 0, 40, 60 and 80 000 trees leucaena ha-1 and three replications, an evaluation from inception to 340 days of age. The results showed statistical difference (P≤0.001) in carbon sequestration with 128.62a, 122.00b, 109.73c y 101.19d 6b C+ ha-1 año-1 for SASP with 0, 40, 60 y 80 thousand plants of leucaena ha-1 , respectively. The major contribution of carbon sequestration was made by coconut, which contributes to 60 to 80% of the SASP. The treatment that incorporated high-density tree legume planting achieved greater carbon sequestration. [ABSTRACT FROM AUTHOR]

BACKGROUND: CO2 laser has been the laser of choice in laryngology for decades and has served as a reference for the development of new types of laser. OBJECTIVES: To analyze the characteristics of CO2 and other types of available lasers, as well as to demonstrate de usefulness of photoangiolytic lasers, specifically KTP, for microphonosurgery. MATERIAL AND METHODS: We reviewed medical literature searching for the otolaryngologic applications of the different types of available lasers, primarily in thefield of laryngology. A comparative analysis -was then conducted: between CO2 and photoangiolytic lasers and between the two most commonly used photoangiolytic lasers: PDL vs KTP. The practical use of these lasers was demonstrated with clinical cases. RESULTS: CO2 laser has a high absorption affinityfor -water, for that it is highly ejfectiveforfine tissue cutting and bloc resections. Photoangiolytic lasers, specifically KTP laser, have a high absorption affinity for oxyhemoglobin, so they are a useful alternative for vascular and tumoral lesions that are in intimate contact with the delicate vocal fold epithelium. CONCLUSIONS: Photoangiolytic lasers, specifically KTP, must be considered a useful alternative in vascularized laryngeal lesions. This particular type of laser offers great advantages over CO2 laser, as lowering the risk of inadequate scarring as well as maintaining the integrity ofvocal fold epithelium and superficial laminapropria (SEP). [ABSTRACT FROM AUTHOR]

Copyright of Anales de Otorrinolaringología Mexicana is the property of Sociedad Mexicana de Otorrinolaringologia y Cirugia de Cabeza y Cuello and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, a field study on hydrocarbon production facilities located at northeastern Venezuela was performed, in order to evaluate the influence of the fluid dynamics in the internal corrosion mechanisms in gas and oil pipelines, caused by the presence of H2S and CO2 . In this way, a new device developed by PDVSA-Intevep was used to carry out a comprehensive study by monitoring the corrosion phenomenon in real production systems. The results show that the main corrosion form is under deposit corrosion, which leads to have pitting damage at different position in the internal surface of the pipelines. According to microscopic analysis, the solid found on the metal surface are related to the presence of sand, carbonates and iron sulfides. The damage location is associated to the hydrodynamic conditions of the production systems, such as the flow pattern and gas and liquid superficial velocities. [ABSTRACT FROM AUTHOR]

Copyright of Revista Fuentes, El Reventón Energético is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Construction industry contributes with about 7% of carbon dioxide (CO2) emitted into the atmosphere. Cement manufacturing process requires high fossil fuel consumption and release CO2 during the burning of limestone (CaCO3). Atmospheric CO2 has concentration of about 0.03% in rural clean environments. CO2 reacts with water vapor to decrease their pH until 5.6. Because of concrete allows the ingress of CO2, it reacts with the alkalis produced during cement hydration. It causes the decrease of concrete pH below 9. Since carbonate ion replaces alkalis, the process is named carbonation that is a manner to monitoring the concrete deterioration exposed to natural environment. Concrete beams with 0.64 and 0.45 water cement ratio (w/c), were exposed to natural marine environment at San Francisco de Campeche City test site. Also an accelerated assay was carried out in a carbonation chamber. The carbonation depth was monitored over the fresh face of cross sections cut at 3, 6 9 and 12 months of exposure by spraying acid-base indicators (timolphtaleine and phenolphtaleine). The w/c ratio plays a determinant role over the advance of carbonation, in both natural weathering and accelerated essays. It is remarkable the importance of the carbonation advance measurements like a parameter on durability of concrete structures. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)